六面锻造和超深冷处理对Cr12Mo1V钢耐磨性能的影响

研究六面锻造和液氮处理对Cr12Mo1V钢耐磨性能的影响。结果表明，六面锻造加余热淬火处理，使钢中碳化物级别降低1～2级，使钢的奥氏体晶粒度降低2级，从而提高了耐磨性。淬火后再经液氮处理，既降低残余奥氏体含量，提高硬度，又降低钢中残余应力，明显地提高了钢的耐磨性。     

Investigations of nitrogen diffusion in austenitic CrNi steels

Parameters of the diffusion of N (up to 0.3 wt.%) in austenitic stainless steels (12 to 19 wt.% Cr, 12 to 16 wt.% Ni, up to 2 wt.% Mo) were determined within the temperature range of 1283–1573K. The small concentration gradients of N were successfully investigated using (1) mechanical serial sectioning technique in combination with either chemical N analysis or X-ray precision lattice parameter determination, and (2) measurements on microsections by means of either electron probe microanalysis or Kossel technique.The diffusion coefficients of N were found to be independent of its concentration. The alloying elements Cr and Mo reduce the N diffusivity in austenitic stainless steels which on the other hand is increased by Ni.     

壮族摩教文化探析

摩教,是壮族先民创造的传统宗教,由布摩传承。摩教崇拜创世神布洛陀为至上神和教主;有整套的法事仪式和相应的经书。摩经是壮族先民企求借助神力来协调人与自然、人与社会、人与人之间的关系以及祈求生存和发展的宗教典籍,折射着壮族的社会发展历程,对研究壮族古代社会经济、文化及道德观念具有重要的历史价值、文化价值和科学价值;摩经中的三元(天、地、水)说是壮族传统的宇宙结构观念,至今仍在民间广为流传;摩经中的公(雄)母(雌)观则是壮族认识世界最基本的哲学思维方式。布摩还以古老的鸡卜作为人神沟通的中介加以广泛应用,并将鸡卜预测与物候历算结合在一起,发明了多功能的骨刻历算器———“甲巴克”,他们经常用它计算日子,预测吉凶,从而使摩教显得更加凝重而神秘     

TA on Mo(W)/Cu(Ag)/S clusters derived with [Cp*MS3]- Kinetics of [PPh4]2[Cp*WS3(CuBr)3]2 and [PPh4]2[Cp*MoS3(CuBr)3]2

Thermal analysis on two new heterometallic sulfide clusters, [PPh4]2[WS3(CuBr)3]2 and [PPh4]2[MoS3(CuBr)3]2 (where PPh4=tetraphenyl phosphonium, =pentamethylcyclopenta- dienyl), was carried out using a simultaneous TG-DTA unit in an atmosphere of flowing nitrogen and at various heating rates. Supplemented using EDS method, their thermal behavior and properties, together with the composition of their intermediate product, were examined and discussed in connection with their distinctive molecular structure as a dianion, which provided some theoretically and practically significant information. Both clusters decomposed in a two-step mode, but without a stable new phase composed of Mo/W-Cu-S formed during their decomposition process as we expected. Based on TG-DTG data, four methods, i.e. Achar-Brindley-Sharp, Coats-Redfern, Kissinger and Flynn- Wall-Ozawa equation, were used to calculate the non-isothermal kinetic parameters and to determine the most probable mechanisms. This revised version was published online in July 2006 with corrections to the Cover Date.     

二硫化钼润滑失效的单电子转移机理研究

ＭｏＳ２是一种性能优良的固体润滑剂，为了考察它的润滑失效机理，在给定的试验条件下，对其在不同温度大气环境中的氧化状态与活性作了顺磁共振和Ｘ射线光电子能谱分析研究．在Ｍｏ混合氧化物的Ｍｏ３ｄ包络峰中解叠出２组峰，分别归属Ｍｏ６＋，Ｍｏ５＋和Ｍｏ４＋这３种化学状态，Ｍｏ５＋在４ｄ轨道上有１个未成对的电子，这是Ｍｏ氧化物中的一种过渡化合状态，具有４ｄ电子构型和顺磁性，可以在从室温到５００℃范围内稳定存在，而且活性较好，在光电离作用下形成Ｍｏ的终态化合物．因此，ＭｏＳ２在摩擦过程中由于周围环境和摩擦热等多种因素的作用，在摩擦表面生成Ｍｏ６＋而失效，这是一种单电子转多过程     

ChemInform Abstract: Crystal Structure of Potassium Sodium Heptahydrogen Hexamolybdocobaltate(III) Octahydrate: An Extra‐Protonated B‐Series Anderson‐Type Heteropolyoxidometalate.

KNa[Co^III(OH)₇{Mo₆O₁₇}] ·8H₂O is obtained by ion‐exchange from a solution of K₃ [Co(μ₃‐OH)₆Mo₆O₁₈] ·7H₂O at ≈pH 1.4 using Amberlite IR120 ion exchange resin followed by concentrating the solution in a hot water bath.     

Organic ligand-free alkylation of amines, carboxamides, sulfonamides, and ketones by using alcohols catalyzed by heterogeneous Ag/Mo oxides

Complicated and expensive organic ligands are normally essential in fine chemical synthesis at preparative or industrial levels. The synthesis of fine chemicals by using heterogeneous catalyst systems without additive organic ligand is highly desirable but severely limited due to their poor generality and rigorous reaction conditions. Here, we show the results of carbon–nitrogen or carbon–carbon bond formation catalyzed by an Ag/Mo hybrid material with specific Ag₆Mo₁₀O₃₃ crystal structure. 48 nitrogen‐ or oxygen‐containing compounds, that is, amines, carboxamides, sulfonamides, and ketones, were successfully synthesized through a borrowing‐hydrogen mechanism. Up to 99 % isolated yields were obtained under relatively mild conditions without additive organic ligand. The catalytic process shows promise for the efficient and economic synthesis of amine, carboxamide, sulfonamide, and ketone derivatives because of the simplicity of the system and ease of operation.     

Methane dehydro-aromatization over Mo/HZSM-5 catalysts in the absence of oxygen: Effect of steam-treatment on catalyst stability

The effect of steam-treatment to HZSM-5 zeolite and Mo/HZSM-5 with a steaming time range of 0.5-1 h on the catalytic performance of methane dehydro-aromatization (MDA) over Mo/HZSM-5 catalyst prepared with impregnation has been studied in detail in combination with the characterization of 1H MAS NMR technique. Both the deactivation rate constant (kd) and the Brnsted acid sites per unit cell were calculated to quantitatively evaluate the stability of Mo/HZSM-5 catalysts treated with steam at 813 K before and after impregnation of molybdenum species, and the corresponding variation of their Brnsted acid sites. The results reveal that a V-shape relationship between kd and the number of B1 acid sites per unit cell is presented on Mo/HZSM-5 catalyst under the tested steam-treatment and reaction conditions.     

爆炸复合1Cr13Mo/45钢连铸辊工艺

鉴于目前连铸辊制造工艺存在的不足,以爆炸复合法制造1Cr13Mo/45钢复合轧辊,并以爆炸复合工艺为研究对象,采用超声波探伤和金相观察等方法,研究药厚和间隙大小对复合界面波形的影响.结果表明:药厚一定的情况下,间隙对复合轧辊界面波形的影响较大;而在间隙一定的情况下,药厚对复合轧辊界面波形的影响不明显.通过实验,获得了该...